It's probably pushing it here (though not wrong) to consider the coordinated [A, B and C] string as a single entity, when 'is' should be chosen. I'd just treat this as a plural string, each element considered separately [A], [B], & [C] which requires are.
– Edwin AshworthMay 02 '21 at 14:39
@EdwinAshworth I see a doubt in your comments, with justice. Could one perhaps say that there is a problem with the sentence, but that it is one of logic or of categories rather than of grammatical number. We are into the kind of sentence I should tend to avoid if I possibly could, since either alternative feels odd. I think I should repeat the definite article with each noun.
– TuffyMay 02 '21 at 16:35
@Tuffy Yes; as it stands, the author seems to want it both ways: a resonance hybrid between [A] + [B] + [C] and [A, B & C]. Three definite articles is (!) what I'd choose too.
– Edwin AshworthMay 02 '21 at 19:06
Which verb should be used depends entirely on what the meaning is to be. I will say it's an unnatural phrasing, though, because "What is the progress of your actions?" is a question that isn't entirely coherent, especially in a context of one "cause" and one "result" since asking for the one result suggests that there is no progress as progress is complete. If the actions are still in progress, then it's premature to ask for their singular result, the singularity of which suggests that you are looking for a specific end result, it being the end result making asking for the one "progress" moot.
– Benjamin HarmanMay 02 '21 at 19:44